The present invention relates to a drum cleaning system for an electrophotographic apparatus.
In an electrophotographic copying machine utilizing semi-moist development, a photoconductive drum or belt is electrostatically charged and radiated with a light image of an original document which causes local photoconduction resulting in an electrostatic image being formed on the drum. A developing liquid containing a toner substance is applied to the drum in such a manner that the toner substance adheres to the areas of the drum in which the electrostatic charge remains, thereby forming a toner image. The toner image is transferred to a copy sheet and fixed thereto to provide a permanent copy of the original document.
However, not all of the toner substance is transferred to the copy sheet during the transfer step and a residual amount remains on the drum. This residual toner substance must be removed from the drum prior to another copying operation to prevent double printing.
Various scraper blades, rollers and the like have been proposed to accomplish the drum cleaning function, but none have proven completely satisfactory in practical application.